Composite materials containing benzoxazines and method for making the same

Patent metadata

Field	Value
Publication number	US-11566106-B2
Application number	US-202016891021-A
Country	US
Kind code	B2
Filing date	Jun 2, 2020
Priority date	Dec 29, 2014
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A curable composition containing more than 80% by weight of a blend of benzoxazines, wherein the blend includes (A) one or more multifunctional benzoxazines and (B) a liquid, non-halogenated monofunctional benzoxazine. This composition has been found to be stable at high temperatures, e.g. 180° C.-250° C., and suitable for making composite materials using conventional techniques such as prepregging and liquid resin infusion.

First claim

What is claimed is:

1. A method for forming a prepreg comprising:
(i) forming a continuous resin film from a curable composition comprising more than 80% by mass of a benzoxazine blend; and
(ii) pressing the continuous resin film onto a layer of reinforcement fibers with application of heat so as to impregnate the layer of reinforcement fibers,
wherein said benzoxazine blend consists of:
(A) a non-halogenated, monofunctional benzoxazine compound that is in liquid form at a temperature in the range of 20° C.-30° C. and has the following structure:

and
(B) a multifunctional benzoxazine component comprising at least one trifunctional benzoxazine compound selected from the group consisting of following compounds:

wherein the mass ratio of (A) to (B) is from 50:50 to 10:90, and
wherein the curable composition exhibits an uncured T g of 30° C. or lower as measured by Differential Scanning calorimetry (DSC).

2. The method of claim 1 , wherein the layer of reinforcement fibers is in the form of unidirectional fibers, a woven fabric or a non-woven mat.

3. The method of claim 1 , wherein the multifunctional benzoxazine component (B) further comprises a di-functional benzoxazine selected from the following compounds:

4. The method of claim 1 , wherein the curable composition is void of or contains less than 5% by weight, based on the total weight of the composition, of any thermosettable resin selected from epoxy, cyanate ester, bismaleimide, and phenol-formaldehyde.

5. The method of claim 1 , wherein the curable composition is void of any organic solvent.

6. The method of claim 1 , wherein the layer of reinforcement fibers comprises fibers selected from carbon fibers, glass fibers, aramid fibers, and combinations thereof.

Assignees

• Cytec Ind Inc

Inventors

• Harriman Mark Edward
• Cross Paul Mark
• Gupta Ram B

Classifications

• C08G73/0233 Primary

  Polyamines derived from (poly)oxazolines, (poly)oxazines or having pendant acyl groups · CPC title

• C08K5/357

  Six-membered rings · CPC title

• C08J5/24

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• C07D265/16

  with only hydrogen or carbon atoms directly attached in positions 2 and 4 · CPC title

• C08L61/34

  Condensation polymers of aldehydes or ketones with monomers covered by at least two of the groups C08L61/04, C08L61/18 and C08L61/20 · CPC title